Method of extracting oils and the like.



' E. v0. BARSTGW 1 T. GRISWOLD, JR.

METHOD OF EXTRAGTING OILS AND THB LIKE.

APPLICATION FILED 00T.9, 1912. f 1,125,920. Patented 1:11119, 1915.

SSHEETS-SHEET 1.

l.. 3J i THUEM..

Mm. kN uw W 771/5111156 MMSK E. 0. BARSTOW da T. GRISWOLD, JR. METHOD 0F EXTRAGTING OILS AND THE LIKE.

APPLICATION FILED OGT,9, 1912.

Patented Jan. 19, 1915.

SSHEETS-SHEET 2.

E. 0. BARSTOW L T. GRISWOLD, JR.

METHOD of EXTRAGTING OILS AND THE LIKE.

APPLICATION FILED 0GT.9, 1912.

1,125,920. Patented 1111.111915.

3 SHEETS-SHEET 3.

/aa /az 1 iig. 4, //2 A123 UNITED STATESy PATENT onirica.

Y Ebwrn'o. Bans'row AND THOMAS enIsWoLD, JR., or MrDLAND, MICHIGAN.

METHOD F EXTRACTING OILS AND THE LIKE.

Specification of Letters Patent.

Patented Jan. i9, i915.

Application vfiled October 9, 1912. Serial No. 724,785.

To all Iwhom it may concern:

Be it known that we, EDWIN O. BAns'row and THOMAS GRIswoLD, Jr., citizens of the United States, and residents of Midland, county of Midland, State of Michigan, have jointly invented a new and useful Improvement in Methods of Extracting Oils and the like, of which the following is a specification, the principle4 of the invention being herein' explained and the best mode in which we have contemplated applying that principle, so as to distinguish it from other inven-n tions. 1

The present improved method relates in general tothe art of separatin' the more readily soluble constituents o materials from their less readily soluble, or insoluble constituents by the process of washing, and in certain of its aspects such present method may be regarded as an improvement on the method of washing, which forms the subject matter of U. S. Letters Patent No. 863,062, issued to Thomas Griswold, Jr., August 13, 1907. Such present method and apparatus relates more particularly, although in no sense exclusively, to the extraction of oils and the like from the material in which they are found, by treatin such material with a suitable solvent in suc fashion as to take up therefrom the oil or the like, the latter being then subsequently separated 'from the solvent which may be utilized over and over again.

The object of the invention is to provide for the economic extraction of such materials.

The advantages over other processes now known to the inventors as being in use, are many. The working capacity or output is relatively very large compared to the investment. he process is continuous and largely automatic, thus reducing labor and cost of attendance to a minimum. A solution or an extract (mixture of solvent and extracted .'l; matter) high in extracted matter is obtained and the amount of solvent left adhering to the material after extraction is relativelyT small, resulting in a relatively low fuel cost for solvent recovery. A relatively very small quantity of solvent in process is required, thus reducing investment therein. The solvent in process is maintained in constant flow either as liquid or vapor, and owing to the manner of its use and recovery,

'z the actual quantity present inthe vvarious portions of `the apparatus withfthe exception of the solvent storage tank is substantially constant, hence any loss of solvent will be at once manifest by change in its surface level 0r depth in said tank, a most important feature, enabling the operator to know at all times, and for any lapse of time, the solvent consumption and the efficiency of recovery, and a sudden change in such level or' depth gives prompt warning of accidental loss by leakage or votherwise before such loss shall have grown to a material amount. The application of heat lin the solvent recovery steps 1s direct, efective and eliicient, insuring a substantially complete and economical recovery, an important point in practical work1ng.

The process is especially well adapted for the use of carbon tetrachlorid as solvent, on account of the small quantity required, the high eiciency of recovery and the promptness with which any loss is made evident, whichV features are particularly important because of the higher relative cost per gallon of this solvent. l

To the accomplishment of the foregoing and related ends, the invention, then, consists of the steps hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain means for and modes of carrying out the invention, such disclosed means and modes illustrating, however, but several of the various ways in whiich the principle of the invention may be use In said annexed drawings :-Figure 1 shows, in more or less diagrammatic form, an arrangement of apparatus for the carrying out of our improvedY process;4 Fig. 2 'is a diagrammatic representation of the ilow of the different materials involved in the carrying on of our improved process; Fig. 3 is a plan view showing a modified form of eX- tractor from that included inthe apparatus of Fig. l; Fig. 4 is a transverse section of such modified apparatus on line 4--'l; and

5 is a broken longitudinal vertical section of the same taken on the line 5 5,

Uli

i ene or the like; and, with slight modifications, for a solvent lighter than water, such as naphtha. The central piece ofapparatus around which the others are grouped, is the extractor proper, a modified construction of which, is illustrated in Figs. 3, 4 and 5. Whatever its form of construction, such extractor is designed to operate on the order of a continuous filter whereon the material to be treated is caused to pass in a layer of greater or less thickness, while it 1s periodically treated with, and separated from, the solvent; in other words, the material and solvent may be regarded as moving in currents whose general directions of flow are opposite, but which currents are caused1 to encounter each other intermittently.

Conining our attention for the present to the form of extractor shown in Fig. 1, it will be seen to consist of a cylindrical drum 1 which, in said ligure, is diagrammatically shown in cross section at right angles to its axis. This drum is rotatable on a shaft 2, suitable means (not shown) being provided for the purpose of rotating the same.. The cylindrical periphery of the drum is corrugated and covered with a pervious lter 3 of suitable material, that forms a continuous band around the drum over the corrugations. The surface of the drum is further divided oft' into a plurality of similar transverse sections 4, .sixteen being shown for the purpose of illustration. Each of these sections is provided with a port 5, such ports 5 opening in the surface of a commutating valve 6 against which is slidably held a stationary take-olf valve 7 provided in the present instance with four ports 8, 9, 10 and 11, the first three of which are respectively connected by means of pipes l2, 13 and 14 with pumps 17, 16 and 15. These pumps are adapted to create a suction through the corresponding pipes and ports and thus through the several sections of the filter cover that happen to be in communication with the respective ports.` The filter drum 1 is inclosed within a tight casing or chamber 18, the lower portion of which constitutes a receptacle for the reception of a mixture of the material to be treated and the solvent used in the extraction process. The material to be treated is fed into the chamber near its bottom by way of a spout 19 and a hopper v20, the latter being attached to the side wall of the chamber, with which it communicates through an opening 21 that preferably lies below the level of the liquid mixture within the chamber. Such level is determined by means of an automatic regulator 22, by which the supply of the solvent to the chamber is controlled, the construction and operation of such regulator being reserved for future description. The level of the'mixture, within the chamber however, is such as to cause the drum 1 to be partiall submerged therein, as clearly shown in ig. 1. The respective discharge lines 23, 24 and 25 from the pumps 15, 16 and 17 lead'to separators 26, 27 and 28 which are adapted to receive the mixed air and solvent (such air and solvent being drawn. through the pumps, as will be presently described), and separate the same by gravity, the solvent passing olf by way of separate pipes 29, 30 and 31 and the air by way of a common branched pipe 32. The air in such pipe 32 will be under pressure, due to the hydrostatic head measured from the level of the li uid in the several separators (such level being indicated by dotted lines) to the out 'letj level of said reservoirs which is the salme in each being indicated by numeral. 33

in each case. Such hydrostatic head is controlled at will by means of an adjustable relief valve 34 connected to pipe 32 and venting into the housing 18. Located above and parallel with the axis of the extractor drum within the casing 18 that houses the same, are two troughs, or feed boxes 35 and 36, the first of which is su plied with fresh solvent by way of pipe 37 from a storage tank 38; the second of which is supplied by the pipe 29 leading from the overflow of separator 26. The overflow of separator 27 is carried to a liquid inlet pipe 39 at the base of the chamber 18 byvway of pipes 30 and 40, a hydrostatic device, which controls the supply of fresh solvent through pipe 37, being interposed between said two pipes 30 and 40. Thishydrostatic -device comprises a vertical stand pipe 41 enlarged at its upper portion to form a chamber, the latter overflowing into the pipe 40 that leads to the liquid inlet pipe 39 at the bottom of theextractor chamber. In the chamber of the device is located a float 42 connected by means of a rod 43 to the lever 44 of a valve 45 in the feed pipe 37 for the fresh solvent. This float, being immersed in the extract in the chamber will obviously rise and fall as the latter varies in density. Assuming the hydrostatic device to be arranged for'dealing with carbon tetrachlorid in extracting an oil lighter than such tetrachlorid, should the extract become poorer in oil and hence heavier, the float will rise, thereby actuating the valve 45 to decrease the How of fresh solvent into the extractor; should, on the contrary, the extract become richer in oil and hence lighter, the float will sink and actuate the .valve to increase the flow of fresh solvent to the extractor. The

Yes

lio

but the overfiow from said e" ma beine-a. The sapersi s .info

which pump 17 discharges, 'is designed norinally to overio'w into a stationary filter `46, separator lis also connected'by means of the pipe 31 with the regulator 22, previously vreferred to, and the extractor chamberby way of -inlet pipe 39. lThe action of this regulator is normally to close the connection 'of the pipe 31 therewith, so long as the mixturefin said chamber is maintained 'at a predetermined level. Should, however, this level fall, a iioat 47 in the regulator will drop correspondingly and thereby open a `lvalve 48 and permit a portion, or all, of the extract overflowing from the separator 28 to be diverted from'filter 46 throu h pipe 31 to the extractor chamber 18. Suc lowering of the level obviously will occur only when the supply of extract overiowing from separator 27 and passing thence through pipe 30, hydrostatic device 41, and pipe 40 to the extractor chamber, is insufficient to maintain the predetermined level in said chamber. The normal course of flow of the solvent may be, for thepurposes of the description, taken to be from the last extraction to the 'filter 46, although in actual operation the volume of this iiow is less than that returned to the extractor, in order to maintain a uniform and constant level in same. Under ordinary operating conditions, the valve 48 is always open and a continuous flow of extract is coming in through it and also a continuous flow is passing forward to the filter 46, the valve serving merel)1 to automatically divide the total flow into two portions. one to the filter, the other to the extractor. The extract as it enters the chamber, whether supplied through pipe 40 or Apipe 31, is mixed with thel untreated material as the latter is drawn away from hopper 20 into the base of the extractor by the action of paddles 49 suitably rotated, as need not be explained. The opening from the hopper 20 into the extractor chamber, being below the liquor level therein, such liquor traps the opening and prevents escape of air and solvent vapor from the chamber 18, andthe downwardly moving mass of material within the hopper forms a stopper which further retards or prevents the vaporization of the solvent which wets the material in the base of the hopper.

Before proceeding with the description of the other associated parts of the general apparatus, the operation of the extractor proper may be advantageously reviewed. It

will be noted, then, that the material, as itis .fed ithrough the hopper into theextractor chamber 18 by the action of the paddles t9, is mixed with the extract iiowing in through thepipe 39, vsuch extract ,being in the main supplied through pipe 31 and valve 48, there vbeing a larger flow of extract returned through such pipe 3l and' valve 48 than through pipe 40, since there is a. considerably larger volume drawn in through the iilter in producing a layer thereon than there is drawn through the same in washing such layer, and the portion divided out and sent forward to the stationary 'filter 46 is relatively small. It will be understood that whenever the level of the mixture in the chamber falls below a predetermined point, the `deficiency is made up by diverting a larger portion of the overflow from separator 28, through pipe 31. The mixture of extract and material, thus produced in the bottom of the extractor chamber, being in contact withthe submergedportion of the filter drum l, a quantity of the fluid extract is drawn from such mixture in the base of the chamber through the submerged sections 4 of the drums cylindrical surface by pump 17 acting through pipe 12 and port 8. A layer of the material is thus caused to deposit on the surface of the drum, such layer forming continuously to approximately uniform thickness as the drum rotates. The material thus deposited on the drums surface as it rises above the level of the mixture is, of course, wet, that is, it includes a considerable content of the extract; how4 ever7 the suction of the pump 17 continues to be exerted upon said layer after it has thus passed out of the body of mixture in the bottom of the extractor chamber until the upper limit of the port S has been passed by the ports 5 in the commutating valve member 6 that rotates with the drum. lmmediately following the breaking of connection with port 8 and pump 1T just described,

communication with the port 9 that is connected with pump 16, such port being normally in register with but three of the sections of thc drums surface at a time` whereas the first port was more extensive, as shown in Fig. 1. The trough or feed box 36 which receives the overow from separator 26 is disposed to discharge the weaker extract received from said separator on the surface of the drum along -a line just safely above that which the sections of said drums surface must reach in order to be in communication with said port 9. The additional flow of solvent thus run onto the material from the feed box is drawn through `the material by the pump 16 and by it conveyed to the next separator in the series, viz. separator 27. The sections l of the drums surface-are next brought into communication in succession 4with port 10 connected with pump 15, the second trough or feed box 35 being -disposed so as to discharge the fresh solvent received from the reservoir 38' onto the layer of material covering the dr-um`s surface along 'a line just beyond that which the sections must reach in order to rst come into such communication with such port 10. Finally the sections, one by one in the illustrated construction, come into register with the port 11. This port is connected with the air line 32 through which the air that is drawn by the several pumps and then separated from the solvent in the separators is returned to the extractor chamber. This air blows through the filter membrane that forms the outer surface of the drum and thus assists in loosening the layer of materi al thereon so that the latter may be easily removed by means of a scraper which delivers the extracted material onto a conveyer 51 that serves to continually convey the same outside of the housing as fast as it is received from the revolving extractor drum. It should be noted at this point that the rate of rotation and degree of suction are intended to be such that not only will the extract or solvent bc sucked through the layer of material, but air from Within the housing will also be drawn through vthe layer, ythus mechanically displacing in a measure the residual solvent or extract between the particles of material'in such layer.

Both air and extract or solvent, of course, v

are drawn into the several pumps and are then delivered into their corresponding separators. This same air, after separation, is available for loosening the layer of exhausted material, no outside air being required to be introduced at any stage of the operation. lt will be further noted that after the extract is separated from the material picked up by the rotating extractor, the solid material remaining on the drums surface` is washed one or more times by weaker extract, and linally by entirely fresh solvent, as the extractor drum rotates; also that the extract from each extraction, as such drum rotates, is kept separate from the extract of all the other extractions and the fresh solvent fed into the box or trough 35 is next fed into the box or trough 36 and is later mixed with the fresh, incoming material at the base of the .extractor chamber.

Such incoming material, it Will accordingly be seen, moves in a general direction substantially,l opposite to that in which the currentof solvent, freshly received at the feed box 35, is caused to move as it is brought intcrmittently into contactual relation with the material as the latter is picked up and carried around the drum. Counting the extractions as Nos. 1, 2, 3, etc., beginning with the fresh solvent wash, and the last extraction, viz., that obtained through the submerged portion of the drum, it will be noted that we have placed the regulator 42,

so that it will regulate according to the de nsitv of extract from the next to the last exl traction. It should be understood, however, 65. that this regulator can be placed in any portion of the circulation so as to regulate according to the density of extract at the preceding extraction; preferabl however, ,We I placeit as shown near the al extraction at which point the extract is nearly full strength. c l

Passing now from the extractor proper, the treatment of the discharged extracted materialdelivered by the drum 1 to conveyer 5l will next be traced. Such conveyer, comprising a closedv tube Within which revolves a screw of usual form, extends to the upper end of a vertically disposed cylindrical chamber 52 that forms a heater Where the solvent remaining in the material is' removed b contact With a counter-current of steam. e screw of conveyer 51 stops short of the opening in the steamer chamber, so that such opening is closed by a plug of the moist material Which serves to prevent the escape of steam or vaporized solvent from, the steamer into the extractor. Within the steamer chamber are arranged a plurality of shelves 53 which open alternately at the center and periphery of the chamber. A central rotatable shaft 54 extends longitudinally of the chamber and carries rakes 55, or like devices, which move over and j ust above the several shelves, beingv adapted to turn over the material on said shelves and to gradually move the same in a spirally inward or outward direction, as the case may be, depending upon Whether the shelf opens centrally or at its periphery. The entering material ,is thus spread out and broken up on the upper shelf, fed gradually across` it, dropped onto the next lower shelf and so onv from shelf to shelf until such material rea-ches the bottom of the chamber Where it is received by the inner end of another screw conveyer 56 that delivers it Without the apparatus. The screw in this conveyer, as in conveyer 51, stops short of the opening in the conveyer pipe so that a portion of the steamed material fills such opening and practically seals the steamer against the entrance of air or the escape of vapor. At the same time that' the material is bein turned over and raked on the several she ves and gradually fed down through the steamer '115 chamber 52, steam is admitted near the base ofthe latter by Way of pipe 57, such steam rising in a zigzag path in contact with the constantly changing surfaces of the body of material that passes downwardly through the steamer as ]ust described. Any excess of such steam, together with the vaporized solvent, escapes finally through a vapor pipe 5b which carries it to a condenser coil 59 in the tank 60. The action of this o posing current of steam on the materia is to 'thoroughly vaporize the solvent mixed with such material, so that substantially all such sol. vent is driven olf by the steam to this condenser coil. From the latter the condensed 13 0 steam and solvent flow by Way of a sight box 6 1' into' a condensation' main 62, wherebyv they are conducted to a separator, Whichlywill be described later. In mentioning the excess of ste'a'i'n"accompanying the solvent vapors, we wishto point out the factthat the solvent vapor willbe greatly inexcess and that the steamispres'ent only in small ai'nountl The amount of steam present willactuallybe de'- pendent upon whether the apparatus is beingforced Aor not. Tf it is bein' 'foi-ced, the excess of Steam Willbe great. fit being worked at a rate suitable to its capacity, the

excess of steam Will'be quite small'. The sup-Ik ply of steam to the'ste'amer chamber by way of pipe 57 is controlled by ja valve 63, which in turn operated by means of a thermostat 64,1no'unted at a suitable point in the wall of the ch'inber 52, so as to be in contact with tlie vapor within the lattei'f Inasmuch as the temperature of such vapor, consisting, as it does, of amixture of steam and solvent,

will va'iv, depending upon the relative proportions of the two ingredients', it follows that' there will be a gradual change of tempei-attire within the steamer varyingl from bottomto top with the different roportions of` steamand solvent vapor, an that there will be some, certain'ftemperatu're which, if maintained at the selected point in the vapor space within the steamer chamber, will insure the practically complete absence of solvent; or solvent `vapor at the base of the steamer. Accordingly,l by properly locating tpe thermostat and adjusting its action1 such t ierm'stat may be adapted'to automatically conlt'rol the steamentering pipe 57, so as to effect a practically complete recovery' of the' solvent in `the material withoutthe Waste of steam.

The course otthe final extract overflowing from separator 2 8 will now be followed, such.extractfirst passing,` as previously indicated,V into ,afffilter 46, the function of whiclififs to reniove any particlesof insoluble materiali-finch may have passed through the filter membrane on the drum. From this filter the liquid extract is then led by way' ot'I piijie 65' in't'othe top ofI a distillation column 66 'which mayy be' of any suitable construction, although preferably made cylindrical, as shown, with its upper portion filled with broken 'coke or similar padiging',l resting upon a grating 67, while'ift'js lower portion is filled with a similar materia'l lresting' upon a second grating -68. S-,eamis admitted into the base of the coli'iinn' by a pipe, 69 in which is aV valve70, i'vliich is controlled by meansof a thermostat 71,' much as in the case of the thermostatically: controlled supply valve 63 of the steamer chamber Such thermostat 7l. isf conveniently located so as to vextend into the between the two' bodies of filling material within the column.` The extract'flows to separate.

coill in the tank 60 fromwhieh the cori--4 densa-te passes through a sight box 76 into the same main 62 that receives the condensate from coil 59. The oil that flows from the bottoni of the column 66 will be emulsified with the condensed water', and thefunction of; the tanks 73, which receive the mixture, is to permit such oil and Water After separation, the water may be drawn off through outlets 77, and if there be any solvent still present in the' oil, steam can be admitted through a pipe 78 branching from pip e.69, sowas to vaporize such solvent whichV is thenconducted through a vapor pipe 9 to a third coil 80 in the tank 60l from which.v the condensate' flows by' way vofV sight box 81' into the con`r densation main' 62.v The oil left in' the tanks 73 may be withdrawn, as desired, by p ipe' 82. The condensation from this several` coils in the condenser, united the coni' densatioir 'main' 6 2, is led yinto tliey separator 8 3, wher-'exa gravitational separation of the solvent from the water formed by the condens'ed steam occurs. The particular forni'l of separator illustrated, in keeping with the' remainder of theapparatus, is primarily designed. for the separation of water from a,= heavy solvent, such as carbon tetrachloridl The water, accordingly', will overflow through a pipe 84 to waste, while thedewatered solvent overfiows through another pipe 85 into the storage tank 38, previouslyf referred to in connection with the description oi"L the extractor.

A gasometer 87 is connected by means of a branched pipe 88 with the'diiferent' pieces of the apparatus, including the Stor-f age tank- 38, the extractor chamber 18, theA chamber 41 containing the hydrostatic device and the several separators 26, 27 and 28 together with 'the filter 46, so as to maintaina uniform vapor pressure throughout the apparatus and avoid loss of solvent vapor. As the body of air or vapor within the extractor housing and above thesurface of' the solvent' in such various parts ofy the apparatus changes in v olume, owing to change of temperature or other cause, the gasometer will rise or fall accordingly.

lt shouldbe observed all 'air or vapor, orva'por mixture` which is drawn by the' pumps 15, 164 and 17 througltthematerial .f

on the rotating-extractor drum 1, comes from Within the housin 18 of said extractor `the relief valve 34 which is setto maintaln a proper pressure upon said port 11. lIn this Way no vaporized solvent 1s lost as no airis discharged froml the apparatus and by displacing solvent inthe material by au' or vaporin this manner a more thorough extraction is obtained at each washing and fewer washings are re uired to attain a definite degree of tota extraction i' and what is also important, the material leaves the drum much drier than it would otherwise be if merely drained without air washing; furthermore' there is less solvent carried over into the steamer 52 and 'corres ondingly less steam is required to be used t ere.

' It will be evident that other ways of applying suction to the drum may be substituted for the pumps shown and an independent air pump may. also be used to furnish Vair for blowin the material at the port 11. It will a so be apparent that other forms of separators than those shown may be used for separating the solvent or extract from the air or vapor.

If superheatedsteam be used 1n 'the steamer for evaporating and deodorlzing, the product leaving at 56 may be made nearly dry, that is free from Waterbut if no superheated steam be used and 1t 1s desired to further dry the materlal after steaming it may be deliveredby the screw conveyer into any form of drler sultable. to the purpose and herein continuously dried as desired. Certain other minor modifications, moreover, would require to be made in the details shown, in order to it the apparatus to work with different solvents, the details shown and described belng d esigned for the use of carbon tetrachlorl'd as heretofore stated; but anyone skilled 1n the use of solvents Will readily understand the nature of the modifications necessary for the substitution of other solvents, and hence the present description is not burdened With .an enumeration of them.

The general operation' of the apparatus asa whole and the various steps included in our improved process or method of extraction, may be best comprehended by reference to Fig. 2, which is in the nature of a ow chart, and shows the movements of material, solvent, oil, vapor, Water, etc., in the apparatus of Fig. 1. This flow sheet is, of course,l purely diagrammatic, but so far as applicable, the same reference characters are employed as in said Fig. 1. In sald flow chart the materials are shown as iowing in bands differently cross-hatched to designate the different constituents, as per the key at the right; thus the material to be treated is shownl in a band divided into three portions, wate1f,'ins'oluble and soluble. Entering the extractor chamber 18, 'this composite material is taken up by the drum l and carriedv *around in the direction of the arrows.` The residuum, stillA containing all three 'ingredient's, but with the proportion of soluble much reduced, is discharged from the extractor -and thence 4conveyed to steamer chamber 52. While v'such material has lost in soluble during its passa e through the extractor, it has no'w an ad ltional lngredient consisting ofthe residual solvent which is not removed in the extractor. In the steamer chamber, the material, with the soluble thus extracted to a minimum, is brought into contact with the current of steam, which passes through the steamer and is condensed at the same time that it eva crates th'e solvent. The latter, together wit any excess of vsteam (which remains uncondensed), passes out into the condenser 60, while the residual material with its content of water increased by the condensed steam, but with the solvent entirely eliminated, passes downwardly and out. Reverting to the extractor, the fresh solvent from the storage tank '38 passes through the material on the drum V1 at A, taking up a relatively small amount of soluble, as represented bythe narrow band. Such solvent with this small content of soluble is then passed a second time through the stream of material at B, this time taking up from the material more soluble, as vshown by the increased Width of the band indicating the latter constituent. The extract (mixture of solvent and soluble) thus obtained is then delivered into the base of the extractor Where it is mixed with incoming material and a third time separated therefrom at C, taking up still more soluble, as shown by the increased width of the band. The repart being returned into the base of the extractor, while the other part, the linished extract as it may be termed, passes into the filter 46 and thence to the column 66. In the 'column the extract is brought into contact with a counter-current of steam which vaporizes the solvent in the extract, and at the same time is itself condensed. The solvent vapor `and any excess of steam will be seen passing out of the top of the column to the condenser 60,l While the oil or other extracted substance, together with a content of Water formed by the condensed steam leaves the column at the bottom and pass into the separating tank 73 where the oil is nally obtained substantially free of water. The solvent vapor and any excess steam sulting extract is divided into two streams,

. I l) after condensation in condenser' 60, are combined with the condensation from the steamer chamber and passes to the separator 83, vwhence the Water is discharged to waste ybeen indicated, relates entirely to the extractor. The apparatus illustrated in the figures just named, in other words, is intended to be substituted more or less bodily for the"extractor in Fig. 1, including the housing orchamber 18 with the rotating drum and other parts inclosed therein. In the present case, however, certain of the pumping and separating elements of the apparatus are as a matter of convenience inclosed along with the filter mechanism, although the exterior connections and the arrangement of the apparatus otherwise remain unchanged. In the extractor shown in Fig. 1, the material to be extracted is first mixed with a quantity of extract and then is given a succession of washings with yweaker extract (finishing withfresh solvent) upon the rotary drum 1, such succes sive washings or extractions following one another relatively quickly. We have discovered, however, that in dealing with at least certain materials, the time element is an important factor in attaining complete extraction; in other words, it is desirable between successive washings to permit the material to steep or soak inthe extract or solvent, as the case may be, for a greater or less time, and when this is done, fewer washingsl will obtain a given degree of extraction, or, with the same number of...washings, a more perfect degree of extraction may be obtained. Not only is this true, but if in addition the material and solvent be mixed mechanically while soaking between washings, or extractions, the effect is increased, this being due undoubtedly to the more rapid diffusion of the solvent within the particles of material .caused by the stirring. The modified apparatus under consideration accordingly comprises, instead of a single filter drum, aseries of such drums (four, 91, 92, 93 and 94 being shown), although the number may be greater or less as desired. These drums are mounted in separate compartments 95, that form sections of a closed tank, the upper portion 96 of which is removable as shown, and may be sealed against escape of vapor by placing water in the lute 97. The material to be extracted is fed in by way of a spout 98 into a hopper 99 which opens into the base of the tank compartment 95 in which is mounted the first drum 91 of the series. The operation of this hopper is identical with that in the previously described construction, and the level of the mixture within the tank is maintained by means o f a regulator 100 similar to the regulator 22 in Fig. 1, and hence not shown lin detail.

While the tank is divided into compartments for the respective drums these compartments are interconnected .by means of pipes 101 (Figs. 4 and 5), so that the same level of liquid is maintained in each. The drums are rotated all in the same direction, as indicated by the arrow in Fig. 4, by means of shaft 102 which extends lengthwise of the tank with one end outside of the same, there to be drivenl in any suitable manner. pinions 103 which mesh with gears 104 mounted on the shafts of the respective drums, such drums being axially alined in order to permit of -this simple driving arrangement. In each compartment, moreover, 'is a short paddle shaft -105 correspondlng to the respective drums, such shafts being driven by sprocket chains 106 from the same shaft that rotates the drums. Likewise associated with each drum is a scraper 107 which operates as the scraper in Fig. 1 to remove the material from the corresponding drum and pass it into a screw conveyer 108, the latter extending throu h the series of compartments alongside o .the drums therein. While such conveyer 1s -thus continuous, the trough in which it runs is provided with openings 109,

so that the material received in the conveyer from one drum may be discharged into'the compartment of the next adjacent drum. The nal discharge end of the conveyer extends without the casing of the inclosing chamber or tank. The shaft'110 of the conveyer screw similarly extends without such casing at the opposite end in order to be connected with suitable driving means, as need not be further explained. In connection with each of the filter drums, there is provided a pump 111 and a separator 112, which serve thelsame functions as .do the corresponding parts of the first-described apparatus. The pumps are operated from This shaft carries i the general drive shaft 102. by means of gears 113. The general construction and mode of operation of the individual filter or extractor drums in this modified apparatus are the same as in the case of the single drum in the first described form of the apparatus, each drum comprising an outer surface of filter membrane divided into sections 114 that communicate by way of ports 115 in a commutating valve member 116 with other ports 119-120-121 in a stationary valve member 118. There are, however, (see Fig. 4), only three ports 119, 120 and 121, in the stationary member in the construction under consideration, the two lowermost of which are connected by branched pipe 122 with the intake of the corresponding pump 111while thel remaining. port 119 is connected with the air dischar e line 123 from the separator 112 into whic such pump discharges. An escape valve 124.- servesl to relieve excessive pressure in this line 112. Port 121h is adapted to communicate only with sections entlrely submerged in the mixture of material and extract in the tank compartment, While the other port 120 communicates with those-sections of the drums surface which have just passed above the level of the mixture in` question. The branch of pipe 122 con-4 nected with this latter port contalns a reducing valve'125 so as to cut down ythe air 'drawn by the pump, through theportion of the filterl not submerged, to a point su1t able to the capacity of the pump and the requirements for compressed air to be su plied through pipe 123 and port 119. t the same time it isrendered possible by this '-device to maintain a suitable degree of suc- ;tion upon the submerged portion of the drum. It Will be understood that this feature of construction can be advantageously incorporated in the case Where but a single extractor drum is utilized, as shown in Fig. 1. While the' air is thus returned to the same drum through the surface of Which it was drawn by the action of the corresponding pump, the separated liquid is ledby Way of pipe 126 to a point in the same -cpmpartment adjacent to the inlet 4for the' material to that compartment, such material being received in the case of the first compartment from the hopper 99, and in the case of each of the succeeding compartments through the respective openings 109 in the conveyer trough as already explained. The point of discharge of these pipes 126 is accordingly close to the paddle shafts 105, so that such incoming material and the liquid maybe immediately mixed and the mixture then pass on into the body of the compartment. The end of each such pipe furthermore dips into a small compartment or trap 127 best shown in Fig. 5, one side of which connects with the pipe 101 that joins the adjacent compartments, while its upper portionopns-into the tank in which the mixture of extract and material is maintained as described. The fresh solvent is fed in by Way of a supply pipe 128, which enters the last of the series of .compartments near the paddle shaft therein Where it is mixed With the nearly extracted material, that is the material which, upon passing around the filter drum in said compartment, is finally discharged from the extractor through the conveyer 108. The flow of the fresh solvent through pipe 128 is controlled by a hydrostatic regulating device 129 interposed in the liquid discharge pipe 126 from the separator in the second compartment, such device including a float 130 that operates a valve 131 in the same fashion as the oat 42 operates the' valve 45 in the apparatus of Flg. l1. The foregoing description is believed to afford a suiicient basis for an understanding of the mode of operation of this modified ap paratus. A supply of material to be extracted is maintained in the hopper 99 that opens into the first of the partments, A way of the pipe 128 through the regulating device 129 to the last, of such series of compartments near the paddle shaft in said compartment. The fresh solvent thus supplied, after being mixed with the nearly extracted material as valready described, and being filtered therefrom by the continuous filtering action of the extractor drum in it now carries a small proportion of the soluble, is passed on to the next compartment, because the volume of extract sucked through the filter drum in any compartment is greater than the volume of solvent fed into that compartment and only as much extract passes on to the next compartment as corresponds to the solvent feed. The last precedin observation will apply to the quantity o extract drawn through each of the succeeding filters, such quantity being greater than the flow of extract tothe respective compartments from the one next adjacent thereto. A 'certain proportion ofthe Weak extract obtained by the operation in this last compartment, will, however, flow over into the next Where it is mixed with the material being discharged into said compartment from the conveyer 108 and is then filtered in turn on the drum in said compartment. This operation continues, stage by stage, until the first compartment in the series is reached, where the fresh material is received into the system. This material will hence obviously be mixed with the strongest extract, so that such extract as isiinally discharged from this'compartment, after being filtered through the drum, -is of approximately the full' desired strength. lThe rate at which this discharge takes place is controlled by the regulator 100 in the same fashion as is the discharge from the last separator in the previously described apparatus controlled by regulator 22, the surplusA extract passing out through an overflow .pipe 132 at a rate equivalent to that at which the fresh solvent is supplied through pipe 128. The treatment of the extract thus finally passing from the extracting apparatus through this pipe as well as the treatment of the material. discharged from conveyer 108 is of course the same in this as in the reviously series of com- .vvhile fresh solvent is fed in by4 extract as it may properly .be called, since iso touched upon further. In the case of this modied construction of apparatus, as in the case of the first described form, i't has not been deemed essential to show minor detalls of construction. Thus the valve mechanism shown in Fig. 4 is diagrammatic for the sake of clearness just as in the case of the valve mechanism associated with the extractor in Fig. 1. In Fig. 5 the valve mechanism is shown as it ma be conveniently, although not necessari y, arranged the stationary take-01T valve 118 being oi ring form slidably mounted lon the drum shaft and in slidable contact with the end 4:tace of the drum through which open the passages that connect with the several sections of the cylindrical lter surface of the drum. This stationary take-o" valve may be held against rotation in any convenient manner and kept in proper contact with the drum face by means o'r1 spring pressure or otherwise as described.

The advantages of the modified construction and course of procedure involved in the use of the apparatus shown in Figs. 3, 4 and 5 are numerous, but will be only brieiy set forth. In the first place the soluble substance in the material being treated is given ample time between extractions to diffuse .and dissolve in the solvent in the series of pools or puddles that are in effect formed by the successive intermixtures, this action being assisted by the mechanical stirring Which such mixtures receive. The size of the filter drums can be made much smaller than in an apparatus of the type illustrated in Fig. l for yielding a given output. Moreover, the several drums are desirably separately mounted as shown, and thus any one of them may be quickly removed in case of necessity, and a spare drum quickly put in its place, all the drums of course being interchangeable. Accordingly. only a short shut-down would be occasioned by an accident to any one of the drums, and this is a very important consideration in a continuous process like the one described. In this modified apparatus, finally, all the pumps. pipes, separators and other fittings associated with `the extractor are inclosed within the casing that incloses the filter drums, thus retaining and saving any solvent, Whether liquid or vaporized, that may i escape by reason of leaky joints. It Will be understood, of course, that the number of washings of the layer of material on any particular drum in this last described apparatus may be increased above that shown as being provided for. As this would involve an arrangement in connection with each of the drums similar in all particulars to that illustrated in Fig. 1, it has not been deemed necessary to separately illustrate this modication in construction.

In each of the several forms of apparatus hereinbefore considered, it will be observed that the material to be treated is caused to pass in a layer 'of any desired thickness on a contlnuouslymoving filter surface, whereon 1t is treated with and separatedfrom the solvent one or more times, such solvent being causedto pass through the material on the filter in a current whose general direction of flow is' opposite to that of the material. In this manner the untreated material is first treated with solvent containing a relatively large amount of extracted substance, then with solvent containing a less amount, and inally with fresh solvent, whereby a thorough extraction of the material and the production of an extract high in extracted matter are obtained. The successive encounters of the solvent with the material being treated occur in the case of the individual rotary extractor or lter while the material is moving with its component particles substantially at rest with respect to each other, and it is to be noted that the order of the successive encounters or contacts of the solvent with the material is opposite to the direction of movement of the latter. Similarly, in the case of the modied apparatus illustrated in Figs. 3, 4 and 5 whereA a series of intermixing and separating steps occur, the order of the successive encounters of the solvent here with the material is opposite to the general direction of movement of the latter through the apparatus regarded as an entirety. For convenience we may speak of the general directions of flow of thecurrents of solvent and material which thus encounter ,each other intermittently as being opposite, it being understood that the reference is to the order ofthe successive encounters of the solvent withl the material in relation to the direction of movement of the latter.

Among the advantages of the process may be enumerated its automatic and continuous character. The weight of material and solvent in process, moreover, is small, in fact is relatively very small compared with other extraction processes in which percolators are used to work the material in batches. Accordingly, the capacity of the apparatus is very considerably greater for the same investment and weight than with the percolator system. It is possible to reduce the solvent loss to a minimum, as also to emplov for such solvent carbon tetrachlorid which has not heretofore been successfully used in commercial practice. As has been pointed out, among other things, it is desirable. where this particular solvent is employed in working feed materials, to completely deodorize the extracted material where. as in the case of seed meals, such extracted material is to be subsequently employed for stock feed or the like.

As indicated on the diagrammatic Fig.

' Atreated, forming a solution, or extract, from the uid solvent employed in our improved which the solvent is finally distilled off, leaving the oil or other extracted substance behind. The residual or insoluble material is that substantially free of oil, etc., the solvent absorbed therein.being recovered as fully set forth in the preceding description. The fresh solvent is th'at which is'thus recovered from the extracted material and from the distillation step, or from other outside sources, and is admitted to the extractor in regulated quantity, has likewise been set forth. Except as thus initially admitted to the extractor, the solvent, it will be understood, is not a fresh or pure solvent, but contains extracted substance in solution in an amount depending upon the number of times it has come into contact with the material being treated, and other considerations. The solvent, once admitted to the system, remains in circulation`,`being used over and over again. Such solvent, it will further be observed, Hows in a substantially closed circuit, the current being, indeed, divided or branched after leaving the extractor, some, containing the dissolved constituents of the material, going in one direction,and some, absorbed in the residue, going in another direction, but such branched currents are united into one current again in passing through the Aextraction stage, as shown in Fig. 2. Accordingly the term closed circuit -7 may be vproperly applied to such solvent flow, and this despite the fact that the solvent may be in the state of a vapor in certain portions of such circuit.

In conclusion it should be explained that the term, solvent,l as herein used, is not to be understood as necessarily to connote only process, but it may also refer to such solvent with more or less of the substance to be extracted carried in solution therein, according as the context may demand. Similarly, the term, air, is meant to 'connote either atmosphere air, or any other gaseous body; or it may refer to the solvent in vaporized state; or to a mixture of such air or other gaseous body With such solvent vapor. The effect of the closed chamber in which the extraction process proper takes place, is to restrict this air, Whatever its specific character, which may come in contact with the solvent by reason of the exposure of the latter in the chamber to such air, to a substantially particular limited body. It vis furthermore appropriate in lthis connection, to refer to the fact that in the case of the steamer chamber in which the material discharged Vfrom Jthe extractor proper is treat ed, as' Wel'las' 1n 'the cas'cf 'the' distillation clnmn inl which the ,final 'extraer is'patea, thel thermostati'c device lgly be arranged' to control-the' supply 'of lirn'tter`ial`'or' of extract 70 process aspect 'of the"`il'veiltiol;v claims" to' th' 85 apparatus having v,been dividedoft' an` presented in 'a separate plicatin fille d De- @amber 24, 1914, seal x c. lsfsgjsaoffother features o f the inverftionvvhich' liavebeen required `to Abe divided out "and separately presented are the method: of and 'apparatus for regulating I'the 'supply'fwsol-.vent tothe mixture vin Ythe extractor "chamberjsuc'h method and apparatus forming'subjct matl ter of-'our copending application"y iile'd' Dei 9` cember 24, 1914, 'Serial No. I878,839fand vthe method of -separating volatilebonstituets illustrated in' the operation ofthe steamer 52 and the distillation column 66, which `fo-I'l'li's the subject matter'of 'co-pending application 100 filed December' 2 1, 19.14, Serial" lTo,' 818,327. Othermodes of applying the principle "of our invention may be employed instead of the one explained, change being made as regards the steps herein disclosed; "provided 10 5 the steps stated byfany of the following claims or the equivalent of such stated steps be employed. 5f We therefore particularly point out and distinctly claim as our invention- 1. The method of lcontinuously separating the more soluble constituents oliematerial froml the less soluble lconstituents thereof,`vvhich consists in causing 'a"con' tinuous current of the material', anda cur- 115 rent of solvent flowing in a closed' circuit, to encounter each other intermittently; and at one point in such current of solvent separating out from the same any dissolved constituents of such material. 120

2. The method of continuously separating the more soluble constituents 'of a material from the less soluble constituents thereof, which consists in causingla continuous current of the material, anda current of solvent flovving in a closed -circut,t encounter each other intermittently, .the order o flthe successive encounters of the solvent' 'with the material being opposite to the-direction of How of Athe latter; and at one poing; in ist such current of solvent separatingout from the saine'anv dissolved constituents ofsuch material.4

3L` The method of continuously separating the more soluble constituents of a material from Athe less `soluble constituents thereof, which consists in causing a' continuous' current of the material, and a current of solvent flowing in a closed circuit, to encounter each other intermittently; at one point in such current of solvent separating out from the saine any dissolved constituents of such material; andre'stricting the airfthat-'may come in contact/Withy the solvent to :a 'substantially particular limited body. 4. The method of continuously separating I the more soluble :constituents of a material and restricting the air' that may come in contactfwith the solvent to a substantially particular-'limited body. 'u

5. The method of continuously separating the nioresoluble constituents of a material from the less'soluble constituents thereof, which consists in causing a continuous current of the material and a current of solvent flowing' in a closed circuit to encounter each other intermittently ina closed chamber, `whereby the air that comes Iin Contact with the solvent 4-is limited to a substantially 'particular limited body, substantially as described.

l6.'The `method of continuously separating the ,more soluble constituents of a material from the less soluble constituents thereof, Which consists lin maintaining a continuous current of 'the material; circulating a body of liuid solvent; and at intervals passing said solvent through said material so as to Washfthe latter, the general direction of flovv of the' solvent, as it thuspasses through said material, being opposite to'that of'such current of material;

7. v'1`lie`n'iethod of continuously separating the more soluble constituents of a material from the less soluble constituents thereof, `which consists in maintaining a'continuousl current ofthe material; circulatinga bodyof solvent; at lintervals passing said solvent through said material so as to wash the '-latter, the general direction of flow of the solvent, 'as'itthus passes 'through said material,being'opposite to that of'such vcurrent"fo-f material;' and restrictingfthe air that maycome'in contact with said solvent to a substantially particular limitedbody'.'

he Wa l. 1.

in la portion of its circuit 'i 10. The method of fill.

8. The method of continuously separat- 1n`g the{more-soluble constituents ofainaterial' from the 'less soluble constituents thereof, which consists in maintaining a ton'tiiifuous vcurrent of the material; circulating' a body of' solvent yinfaA closed circuit; and" at intervals =passing s'a'id solvent ing opposite lto'thatoyf suchcurrent of ma- 9. The method of'continuously separating the mresoluble constituents'of a material from the less soluble constituents thereof, which vconsists iii continuouslymoving said material in one'y generalj'direction, :supported on ya liltersur.'v ace; circulating a 'body of closed circuit, such solvent flowingin a genfluid solvent in 'a eially o'pposite direction fromsuch material; and at'intervals passing sucli oppositely fiwi'ng solvent through said material whilel supported on such .filter surface.

continuously separatingtlie more soluble constituents of a Inater'ia'l`v from the less soluble constituents ther'eof, which -consists in continuously moving said material'in one general direction, supported' on' a filter surface; circulating a `body of liiuidSQlVent, such solvent i'ii a poi-tion of its circuit owing'in a general opposite direction from such material; at intervals passing such oppositely flowing solvent through said material While supported on such filter surface; and restricting the air that may come in contact with such solvent to a substantially particular limited body.

1l. The method of separating the more soluble constituents of a material from the lessv soluble constituents thereof, which consists in movin@r said material, supported on the surface ofD a rotary filter; at intervals passing a fluid solvent through said matci'ial while thus supported and restricting the air that may come in contact with the solvent being restricted to a substantially particular limited body.

l2. The method of separating the more soluble constituents of a material from-the less soluble constituents thereof, Which consists in supporting said lmaterial oii a continuously lmoving filter surface; at intervals passing a fluid-solvent through said material While thus supported; and limiting the air that comes in contact with the solvent to a substantially particular body, sub- `stantially as described.

13. The method of separating the more soluble constituents of a material from the less. soluble constituents thereof, which corisists-in supporting said material on a filter surface ,continuously rotating iii the same direction; vmaintaining a. current of Huid Y rection; at intervals passing sal less soluble constituents thereof, which con-` v 4soluble constituents of a material from the less soluble. constituents thereof, which consolvent flowing inv a generally op o site di` solvent through said material'while thus supported'; and limitin .the a1r that comes in contact with the s 'o vent to a substantially particular body, substantially as described. 14. The method'of separating the more soluble constituents of a material fromthe sists in mixing the material withfa iiuid solvent;l separating such" solvent and ymaterial byiiltration; and mechanically d lsplacing residual solvent from said material with a1r.

15. The method of separatingthe more soluble constituents of a material from the less soluble constituents thereof, which 00nsists in causing currents of the materialand a fluid solvent whose general directions of iiow are opposite to encounter each.- other intermittently; and mechanically displacing residual solvent from said material with air after each encounter.

' 16. The method of separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in maintainin currents of said material and a fiuid Vso vent, respectively, owing'in general opposite directions; at 1ntervals washing -said material W1th said solvent; and mechanically displacing resldual solvent from said material with air after each such washing.

17. The methodof separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in maintaining currents of said material and a fluid solvent, respectively, flowing in general opposite directions; at intervals passing said fluid solvent through said material on a suitable filter: and passing a current of air through said material after thus passing said solvent therethrough.

18.' The method of separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in moving said material, supported ona filter surface; at intervals passing a fluid solvent through said material While thus supported; and passing a current of vair through said material VvaJ'ter thus passing said solvent therethrough.

19. The method of separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in moving -said material in one general direct-ion, supported on a filter surface; maintaining a current of fluid solvent flowing in a generally opposite direction; at intervals passing said solvent through said material while thus supported; and passing a current of air through said material after thus passing said solvent therethrough.

20. The method of separating .the more soluble constituents of a material from the htslitie 'residual lsolvent from said material. after 22, solubleconstituents of a material from the. A

thereof,-v vvvhich confloware ogpositeto encounter eachotherinnt vand mechanically displacing each with the same air used. over and over again.

21.; Themethod of separating the more 1 sists in maintaining currents of said material and. a iiuid solvent,jrespectvely, iowing 1n genera-lo positedirections; at intervals Washing with the same air used-over Aand overagain. Y

The method of separating the more.

less solub e constituents thereof, which con- "sists in vmaintaining currents of said' material -and arfluid solvent, respect1vely.,'iow

ing in general opposite directions; at intervals passing sald fiuid solvent through said material on va suitable filter; and passing a current of air which has previously been so used through vsald material. after thus passing said solvent therethrough.

23. The method vof separating the more soluble constituents of-'a material from thev less soluble constituents thereof, which consists in moving sa-id materaLsupported on a filter surface; at intervals passing a fluid solvent through said material While I thus supported; and passing a current of the air which has previously ,been soused through said material after thus passing said solvent therethrough. 1 v Y 24. The method` of separating the more soluble constituents of a material fromthe less solublejconstituents thereof, which consistsin moving said material in one generalv direction, supported on a filter surface;

malntaining a current' of Huid solvent flowmg in a generally opposite direction; at intervals passing said solvent through sai i. material while thus supported; and passingacurrent of the air which has previously, been so used through said material after .thus passing said solvent therethrough.

25. The method of separating the more soluble constituents of a material from the less soluble constituentsthereof, which consists in intermixingsuch material with a suitable solvent; thereupon separating Such solvent, with its content of dissolved material, from the undissolved portion of such material;` moving the latter with its component particles substantially at rest with respect to each other; and causing a current of stlilvent to encounter such moving materia 26. T'hefmethod of separating the more .I

27. The method of separating the moreA soluble constituents of a material from the less soluble constituents thereof, which consists in intermixing such material with a suitable solvent; thereupon separating such solvent, with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest With respect to each other; and causing a current of solvent to encounter such moving material a plurality of times, the order of the l successive encounters of the solvent with the material being opposite to the direction of movement of the latter.

28. The method of separating the more soluble constituents of a material from the less soluble constituents thereof, which consists-in intermixing such material with a suitable solvent; thereupon separating such solvent, with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect to each other; causing a current of solvent to encounter such moving material; intermixing the solvent with content of dissolved material resulting from such encounter, with more material to be treated; and so on asY before.

29. The method of separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in intermixing such material with a suitable solvent; thereupon separating such solvent, with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect to each other; causing a current of solvent to encounter such moving material a plurality of times; intermixing the solvent with content of dissolved material resulting from the last of such encounters, with more material to be treated; and so on as before.

30. The method vof separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in Yintermixing such material with a suitable solvent; thereupon separating such solvent, With its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect to each other; causing a vcurrent of solvent to encounter such movmg'materlal a `plurality of times, the order of the successive encounters of the solvent with the material being opposite to the direction of movement of the latter; intermixing the solvent With content of dissolved material resulting from the last of such encounters, with more material to be treated; and so on as before.

31. The method of continuously separating the more soluble constituents of a mate'rial from the less soluble constituents thereof, Which consists in intermixing such material with a body of suitable solvent; thereupon separating such solvent, With its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect to each other; and causing a current of fresh solvent to encounter such moving material.

32. The method of vcontinuously separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating such solvent, with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest With respect to each other; and causing a current of fresh solvent to encounter such moving material a plurality of times.

33. The method of continuously separating the more soluble constituents of a material from the less soluble constituents thereof, whichV consists in inter-mixing such material with a` body of suitable solvent; thereupon separating such solvent, with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect to each other; and causing a current of fresh solvent to encounter such moving material a plurality of times, the order of the successive encounters of such current of solvent with the material being opposite to the direction of movement of the latter.

84'. The method of continuously separating the more soluble constituents of a inaterial from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating such solvent, with its content of dissolved material, from the undissolved portion of such material; moving of solvent in the first step; intermixing moremat'erial t'be treated ivithsuli of solvent; and'so on as before.

I he imethod of continuously separating 'the' more soluble constituents of a ma'- -teria'l from' the less soluble constituents dissolved portion of such material; moving the latter with its component'p'articles substantially at rest' with respect to each other; causing a current of 'fresh' solvent to "en' counter' such moving material a plurality f times; adding the solvent with content of dissolved material resulting 'from vthe last of such' encounters to the body of solvent in the'iirst step; intermixing more 4material to be treated `With 'suoli body ofs'olvent; and so on as before.

36.- The' method of continuously separating the more' solublev constituents of a material 'from' the less soluble constituents thereof, which -consists in intermixing such material with a body of suitable solvent;

thereupon separatingsuch solvent, With its contentof dissolvedmatcrial, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect toeach other;

causing a current of fresh 'solvent tox encounter' such moving material a" plurality ofl times, -the order of the successive encounters of the solvent with the material being opposite to the direction of movement of the latter; adding the solvent with content of dissolved material resulting from the last of such encounters-to the body of solvent in the first step; intermixing more material to v be treated with such body of solvent; and so on as before.

37. The method of continuously separating the more soluble constituents of a material from the less soluble constituents 'Y thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating the extract, consisting of such solvent with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest With respect to each other; recovering the solvent from such extract; and causing a current of such recovered solvent to 'encounter such moving material.

38. The method of continuously separating the more soluble constituents of amaterial from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent;

thereupon separating the extract, consisting of such solventl with its contentl of dissolved material, -from the undissolved portion of such material; moving' the latter 'with its component .particles substantially at rest Witjlfiismecttfieach other; recovering the solvent"iifom 'such extract; and' causing a flfht olfx such"'recoveredsolvent to encounf 1"""sifiihl ln'ovingfmateriall a 'plurality of "39Q' The method of continuously separating the mo'resoluble 'constituents 'of mat'rialfrm the less soluble constituents thereoff'wliich consists in intermixin such material /vith a body of suitable so vent; thereupon separating the extract, consisting of, 'sch 'solvent lWith its'content of dissolved material, from' th'e undissolved portion of such materia-l' movin'g'th'e latter with lits component particles -substantially at rest with re's ectto each other; 'recovering the solvent f r'o'in suC'h'ZeXtr'act; and causing 'a current of 4'such recovered solvent to encounter such moving I'na'teriall a' plurality of times, 'the 'order 4ot the successive encounters ofi's'uch current offrecover'ed solvent with he materia' -bei g opposite to the direction ofinove'mentof'th'lattei.

49", The Imethod of continuously separat` ingthe 'more soluble constituents of a material from the less soluble constituents thereof," which1 consists in intermixin 'such material with' a'body of suitable solvent; thereupony separating the extract, "consisting f 'such solvent With lits content of dissolved matrialgffrom the' undissolvd portion of suchjlmaterial; moving the 'lattenwith its corn'po''i'entV 'particles `substantially at rest with resp'ect'to each other; recovering the solvent from` such extract; causing a current of'such recovered solvent to encounter such movin4 material; adding the solvent with centen ofdissolved material'resulting from such encounter to the body of solvent in the step';interinixing more material to be treated with such bodyof solvent; and soon as before. y

"41."Tl1'e method of continuously separat'- ing the more'soluble constituents of a'material 'from' 'the less soluble constituents tlnereof,'virl1'ich` consists in intermixing such material with a body ofv suitable solvent; thereupon separating the extract, consistin ofish solvent with 'its' contentof dissolve material, from the undissolved'portionof suchmmaterial; moving the latter' with its component particles substantially at 'rest with nes ect to each other; recovering the solvent om such extract; causing 'a curretbf such' recoveredl solvent to encounter suoli oving material 'a plurality of times: add'n 'the ySolvent With content' of dissolved material resulting from the last of such encounters to tlie'body'of' solvent in the first step'" 'intermixin 'm'ore material 5to "be treated with such 'ody of solvent 'andso on as'before 4.2L` The method of continuously separatingv more' soluble constituents of." a material .from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent;

thereupon separating the extract, consisting of such solvent With its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest With respect to each other; recovering the solvent from such extract; causing a current of such recovered solvent to encounter such moving material a plurality of times, the order of the successive encounters of such current of recovered solvent with the material being opposite to the direction of movement of the latter; adding the solvent with content of dissolved material resulting from the last of such encounters to the body of solvent in the first step; intermixing more material to be treated With such body of solvent; and so on as before.

43. The method of continuously separating the more soluble constituents of av material from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating the extract, consisting of such solvent With its content of dissolved material, from the undissolved portion of such material; moving the latter With ,its component particles substantially at rest with respect to each other; and then discharging the same; recovering the solvent from such extract and' discharged material; and causing a current of such recovered solvent to encounter such moving material.

-l-l. The method of continuously separating the more soluble constituents of a material from the less solublev constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating the extract, consisting of such solvent with its content of dissolved material, from the undissolved portion .of such material; moving the latter with its component particles substantially at rest with respect to each' other; and then discharging the same; recovering the solvent from such extract and discharged material; and causing av current of such recovered solvent to encounter such moving material a plurality of times.

45. The method of continuously separating the more soluble constituents of'a material from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating the extract, consisting of such solvent with its content of dissolved material, from the undissolved portion of such material; moving the latter with its component particles substantially at rest with respect to each other, and then discharging the same; recovering the solvent from such extract and discharged material;

and causing a. current of such recovered solvent to encounter such moving material a plurality of times, the order of the successive encounters of such current of recovered solvent with the material being opposite to the direction of movement of the latter.

46. The method of continuously separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating the extract, consisting of such solvent with its content of dissolved material, from the undissolved portion of such material;moving the latter, with its component particles substantially at rest with respect to each other, to a point of discharge; recovering the solvent from such extract and 'discharged material; causing a current of such recovered solvent to encounter such moving material; adding the solvent With content of dissolved material resulting from such encounter to the body of solvent inthe first step; intermixing more material to be treated with such body of solvent; and so on as before.

47. The method of continuously separating the more soluble consituents of a materia-l from the less soluble constituents thereof, which consists in intermixing such material With a body of suitable solvent; thereupon separating the extract, consisting of such solvent Vwith its content of dissolved material, from the undissolved portion of such material; moving the latter, with its component particles substantially at rest with respect to each other, to a point of discharge; recovering the solvent from such extract and discharged material; causing a current of such recovered solvent to encounter such moving material a plurality of times; adding the solvent with content of dissolved material resulting from the last of such encounters to the body of solvent in the first step; intermixing more material to be treated with such body of solvent; and so on as before.

48. The method of continuously separating the more soluble constituents of a material from the less soluble constituents thereof, which consists in intermixing such material with a body of suitable solvent; thereupon separating the extract, consisting of such solvent With its content of dissolved material, fromthe undissolved portion of such material; moving the latter, with its component particles substantially at rest with respect to each other, to a point of discharge; recovering the solvent from such extract and discharged material; causing a current of such recovered solvent to encounter such moving material a plurality of times, the order of the successive encounters of such current of recovered solvent With the material being opposite to the direction ist I r .:M- -i 1;. if .z'l ofmovement of the latter; addlng the solvent with content .of dissolved material resulting from the last of such encounters to the body of solvent in the first step; mtermixing more material to be treated with such body of solvent; `and so on as before.

49. Inan extraction process using -a volatile solvent, the steps whichconsist 1n supporting a continuous current of vthematierial ona moving. filter surface; continuously treating such current lofmaterial with. a current of the solvent, thereby producing an extract'and leaving the material -spent.;.re covering solvent from .the extract; returning such .recovered solvent tothe .current used in treating the material; and restricting. the air which may..come into. contact with the solventin the foregoing steps to a substantially particular limited amount.

50...In an extractioniprocess usingfa volatile solvent, the steps which consist in supporting a continuous current of .the. .mate rial on a moving filter surface; continuously treating such current of material' with. a

current of the solvent, .thereby producingan extract and leaving the material spent; recovering solvent `from the spent material; returning such recovered solvent' to the current used in treating: the material; and restricting the air whlch may come into Acontact with the solvent. in theforegoing steps to a substantially particular limited amount.

51. .In an extraction process usinga volatile solvent, the .steps which consist in supporting a continuous current of the material on a moving filter lsurface;continuously treating. suchcurrent' .of material with :a current of the solvent, thereby producing an extract andleaving the material spent; recovering-solvent fromthe extract and spent material; returning such recovered solvent to the current usedin treating-the material; and restricting the air which may .come into contact with the .solventin the-foregoing steps-to a substantially particular limited amount. l f

52. In a method of the.; -.character described, the steps which .consistin mixing a supply ofthe material tobetreated with a fluid solvent containing the extracted substance; drawing a layer .of the l resulting mixtureonto a movable filter, Lwhereby suchsolvent is separated from the material; Aand subsequently passing fresh solvent through the material on said filter.

53. In a method of the-.character Idescribed` the steps which consist in vsimultaneously and lcontinuously mixing a.su'p ply of the.untreated. material with a fluid solvent containing .a .certain amount of the extracted substance; drawing a layer of the resultingmixture onto the surface of .a rotary ilter; drum, whereby such solvent :is continuously separated. from. the material and then pass-ing solvent containing a rela- Ms-i "uv-"|- l.'. tively. smaller amount 'of such substance than fthe solvent .used `in the first step through .the material on said filter.

In a method of the character described,

the steps which consist in simultaneously and continuously mixing a supply of the untreated material with a fluid solvent containing a certain amount of the extracted substances;

drawing a layer of the resulting mixture onto the surface of a rotary filter drum, whereby such solvent-is continuously separ rated from the material; and then ,passi ing solvent containing a relatively smaller amount .of such substance than the solvent M used in the first step through the material on said filter, the solvent from such last described step being mixed with the materialin the first described step.

. 55.;In a method fof the character-described, thev steps which consist in .simul taneously and continuously mixing ,a lsupply of the untreated material. with a fluid solvent containing a certain amount of the extracted substance; drawing ala er ofthe resulting. mixture onto. the sur ace. of a rotarviilter drum, whereby such .solvent iscontinuously separated from the material; passing.. solvent. containing -a relatively smaller amount of such substance .than-the extracted substance; drawing a layer of the resulting mixture onto the surface of a rotary. filter drumwhereby such solvent is continuously separated, from the material; passing; solvent containing a relatively vsmaller .amount ofvsuch substance than the solvent used in .thefirst step through .the material on said filter; andv then passing fresh solvent therethrough, the solvent from the nextto last described step being mixed with the material in the first described step. ,57. In ,a method of .the character ,described, .the steps which consist in feeding the material to be treated into' a mixture of fluid solvent. landpreviously 'fed material; drawing. a layer l,of the resulting mixture by...suction. ontov a movable filter surface, whereby.- suchsolvent. is in part' separated fromgthe material; and then. .drawing a current. of air. through such layer, thereby mechanicallydisplacmg .residual solvent..

58. In .a :method of the character describedth.efsteps which consist4 in continuously feeding a supply of the material to be treated into a mixture, of fluidsolvent and previously. fed material ;l drawing alayer of, the resulting mixturelby. suctiononto the surface of a rotary filter, whereby such los maa-aaa' sol-vent is continuously'separated from thev rated from the material; and then drawlng.

a body of :air through such layer over and over again., thereby mechanically displacing residual solvent.

60. In amethod of .the character described, the steps which consist in continuously mixing a supply of the material to be treated with a i-uidgsolvent drawing alayer of the resulting mixture by suction onto the surface of a rotary lter, whereby such solvent is-continually separated from the ma terial; continuing the suction to thereupon draw a current of air through such layer, thereby displacing residual solvent and limiting the air thus used, so that substantially the'same air will =be used over and over for this purpose.

61.l In a method of the character described, the steps which consist in continuously feeding a supply ofthe untreated material into a mixture-of iiuid solvent and previously fed material; drawing a layer of the resulting mixture by suction onto a movable -filter surface, whereby such solvent is in part separated from the material; continuing such suction to draw a current of air through such layer, thereby displacing residual solvent; and subsequently drawing fresh solvent, and air through such layer by suction.

62. I'n a method of xthe character described, vthe steps which consist in continuously mixing-a supply of the untreated material with a fluid solvent; drawing a layer of the resulting mixture 'by suction onto a movable filter surface, whereby such solvent is in partseparated from the material; continuing such suction to drawv a current of air through such layer, thereby displacing residual solvent; subsequently drawing fresh solvent, and air through such layer by suction and limiting the air thus used, so that substantially the same air Iwill be used over and over again for this purpose.

63. In a method of the character described, the steps which consistin continuously mixing a supply of the untreated material with a Huid solvent containing a certain amount of the extracted substance; drawing a layer of Vthe 'resulting mixture onto a moving filter surface, whereby :such solvent is continuously separated 'from the material; continuing such action to 'draw a current of air through such layer, thereby of air through.

displacing residualsolvent; then drawing sol-vent and air again through such layer by suction, such latter solvent containing a relatively smaller amount of such substance thanthe solvent used in the first step and lunltlng the airth-us used, so that substantially the same air will be used over and over again. V

64. ln a method ofl the character described, the steps which consist in continuously mixing a supply of the untreatedmaterialwith a fluid solvent containing a certain amount of the extracted substance; drawing a layer of the resulting mixture onto a moving lter surface whereby such solvent is continuously vseparated from the material; continuing such suction to draw a current of air through such layer, thereby displacing residual solvent; then drawing solvent and air again through such layer by suction, such latter soivent containing a relatively `smaller amount of such substance than the solvent used in the first step, limiting the air thus used, so that substantially the same air will be used lover and over again; and using the solvent from such lastdescribed step to mix with the material in the lfir-st described step.

65. IIn a method Yof the character described, the steps which consist n continuously mixingv a supply of the untreated material with a fluid solvent containing a certain amount of the extracted substance;

drawing a Vlayer of the resulting mixture onto a rotating :filter surface whereby such dan? tti

Sli

solvent is continuously separated from the material; continuing such suction to draw a current of air through such layer, thereby displacing residual solvent; then drawing solventland air again-throughsuch layer by 'suction a plurality of times, fresh solvent being used the last time and the solvent resulting therefrom fbeing used in the preceding suction step and then, finally, mixed with with thematenal in the ir'st described step, and limiting the air thus used, so that substantially the same air will be used over and over again.

66. In a 'method of the character described, the steps which consist Vin mixing the material to fbe treated with a fluid solvent; drawing a layer of the resulting mixture bysuction onto a movable filter surface whereby such solvent is separated from the' material; continuing the' suction to thereupon draw a current of air through such layer, thereby displacing residual solvent; and then blowing the same air through such layer in` the opposite direction to free the latter from theilter surface.

6?. 'In a method of the character described, the steps which consist in continuously mixing a supply of the material to be treatedwitha fluid-solvent; drawing a layer of the resulting mixture by suction onto a 

